Arab states need to promote freedom at home and resist Iran's nuclear ambitions, George Bush said yesterday, while insisting in the face of widespread scepticism that he is committed to achieving peace between Israel and the Palestinians.

The US president used a speech in the Egyptian resort of Sharm el-Sheikh to appeal to leaders in the region to take the future into their hands and "treat their people with the dignity and respect they deserve. Too often in the Middle East politics has consisted of one leader in power and the opposition in jail," he told the World Economic Forum (WEF).

"The light of liberty is beginning to shine," he added, praising advances for democracy in Turkey, Afghanistan, Iraq, Morocco and Jordan, but only hinting at stagnation and repression in Saudi Arabia and Egypt, his two stops after joining Israel's 60th anniversary celebrations in Jerusalem last week.

Bush made an effort yesterday to express sympathy for the Palestinians - "who have suffered for decades and earned the right to a homeland of their own" - after Arab anger at his highly sympathetic speech to the Israeli parliament. In that address he mentioned the proposed Palestinian state only once, though it was he who launched the now badly faltering Annapolis talks last November with the goal of reaching agreement by the time he leaves office next January.

As Bush ended his visit to the Middle East yesterday an audio recording purporting to be from Osama bin Laden surfaced on Islamist websites in which the

al-Qaida leader urged Muslims to break the Israeli-led blockade of the Hamas-controlled Gaza Strip and fight Arab governments that deal with the Jewish state.

"The duty to break this blockade falls upon our brothers in [Egypt] as they are the only ones that are on the border," Bin Laden said. "Each one of us is responsible for the deaths of our oppressed people in Gaza and dozens upon dozens have died due to this oppressive blockade."

Hamas gunmen blasted open the Rafah border crossing to Egypt for several days early in the year until the Egyptian authorities moved in troops in February and closed it again.

The Palestinian president, Mahmoud Abbas, told Bush about his concerns over the Knesset speech when the two met in Sharm el-Sheikh on Saturday. "We do not want the Americans to negotiate on our behalf," Abbas said yesterday after talks with the Egyptian president, Hosni Mubarak. "All that we want from them is to stand by [our] legitimacy and have a minimum of neutrality."

In his WEF speech, Bush also attacked Syrian and Iranian support for the Shia movement Hizbullah in Lebanon. "Every peaceful nation in the region has an interest in stopping these nations from supporting terrorism," he said.